Tight-binding ‘dihedral orbitals’ approach to electronic communicability in macromolecular chains

• Published in: Chemical physics letters 2007-11, Vol.449 (1), p.216-220
• Main Authors: Estrada, Ernesto, Hatano, Naomichi
• Format: Article
• Language: English
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2007.10.028

The thermal Green’s function of a linear (macromolecular) chain is defined using a tight-binding approach. We use orbitals centered on dihedral angles to build molecular orbitals. This Green’s function represents the electronic communicability between dihedral angles of the macromolecular chain. It is useful in differentiating protein molecules of different types of conformation and secondary structure. An electronic orbital of a dihedral angle of a molecular chain is introduced. A tight-binding Hamiltonian on the basis of the dihedral orbitals is defined. This yields the Green’s function between two dihedral angles of the chain. It is revealed that the Green’s function, which we refer to as the electronic communicability, is useful in differentiating protein molecules of different types of conformation and secondary structure.